This invention relates to a new antibiotic substance, designated as CP-63,517, which was isolated from fermentation of a new strain of the genus Streptomyces isolated from a soil sample collected in Okayama Prefecture, Japan and assigned the code number N497-34. Structurally the new antibiotic of this invention is a new member of the acidic polycyclic ether (ionophore) antibiotics. This family of antibiotics includes dianemycin [J. Antibiotics, 22, 161 (1969)] and ibid., 33, 137 (1980); monensin [J. Amer. Chem. Soc., 89, 5737 (1967)]; salinomycin [J. Antibiotics, 27, 814 (1974)]; Antibiotic TM-531 disclosed in U.S. Pat. No. 4,269,971 and Antibiotic 53,607 disclosed in U.S. Pat. No. 4,361,649.